Oklahoma State University–Stillwater

About: Oklahoma State University–Stillwater is a education organization based out in Stillwater, Oklahoma, United States. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 18267 authors who have published 36743 publications receiving 1107500 citations. The organization is also known as: Oklahoma State University & OKState.

A Conceptual Framework for Ordered Logistic Regression Models

Abstract: Ordinal-level measures are very common in social science research. Researchers often analyze ordinal dependent variables using the proportional odds logistic regression model. However, this ‘‘traditional’’ method is one of many different types of logistic regression models available for the analysis of ordered response variables. In this article, the author identifies 12 distinct models that rely on logistic regression and fit within a framework of three major approaches with variations within each approach based on the application of the proportional odds assumption. This typology provides a degree of conceptual clarity that is missing in the extant literature on logistic regression models for ordinal outcomes. The author illustrates the similarities and differences among the different models with examples from the General Social Survey and the American National Election Study.

Electrophoretic Deposition of Latex-Based 3D Colloidal Photonic Crystals: A Technique for Rapid Production of High-Quality Opals

Abstract: Three-dimensional colloidal crystals have been grown by electrophoretic deposition on ITO glass supports from aqueous-ethanol colloidal solutions of monodisperse submicrometer-sized negatively charged polystyrene latex spheres. The technique offers the possibility to produce uniform single-crystal colloidal multilayers on the time scale of minutes, which is a drastic acceleration in comparison with the gravity sedimentation technique that needs weeks or even months. SEM and AFM images of colloidal crystals reveal that close-packed 3D fcc ordering of the latex spheres extends over large areas. Electrophoretically deposited colloidal crystals show a pronounced photonic stopband in the visible spectral range in the normal incidence transmission spectra with a position depending on the size of latex spheres. The electrophoretic deposition has also been used for the impregnation of 3D colloidal crystals with luminescent CdTe nanocrystals. The luminescence spectrum of CdTe nanocrystals shows a dip at the wavele...

A Self Adaptive Penalty Function Based Algorithm for Constrained Optimization

Abstract: This paper proposes a self adaptive penalty function for solving constrained optimization problems using genetic algorithms. In the proposed method, a new fitness value, called distance value, in the normalized fitness-constraint violation space, and two penalty values are applied to infeasible individuals so that the algorithm would be able to identify the best infeasible individuals in the current population. The method aims to encourage infeasible individuals with low objective function value and low constraint violation. The number of feasible individuals in the population is used to guide the search process either toward finding more feasible solutions or toward finding the optimum solution. The proposed method is simple to implement and does not need parameter tuning. The performance of the algorithm is tested on 13 benchmark functions in the literature. The results show that the approach is able to find very good solutions comparable to other state-of-the-art designs. Furthermore, it is able to find feasible solutions in every run for all of the benchmark functions.